1. Field of the Invention
The invention relates to a contact shoe assembly for an electric train. More particularly, it relates to a contact shoe assembly in which the contact shoe moves vertically and can bend backward to ensure full contact with upwardly-facing power rails and any obstructions that lie on the power rails.
2. The Prior Art
Contact shoes are known according to the prior art for providing power to electric trains by sliding along a power rail that extends parallel to the support track. The contact shoe extends laterally outwardly from a lower part of the train to which it is mounted. The relative height of the power rail with respect to the support track varies due to numerous factors. Various track systems exist which specify different distances between the power rail and the support track. At grade crossings or track junctures, the power rail tapers off to provide necessary gaps therebetween. In addition, normal wear resulting from use causes variations in the height of the power rail. As a result, the contact shoe is required to move to maintain contact with the power rail as its position varies.
Typically, the arm carrying the contact shoe is pivotally mounted, as can be seen in U.S. Pat. No. 4,042,081. While the pivoting arm allows the contact shoe to effectively move vertically, the contact shoe is oriented horizontally at only one position. At all other heights, the contact shoe is oriented at an angle which results in uneven wear on the contact shoe and the power rail. While purely vertical height adjustment on the contact shoe is known from U.S. Pat. No. 1,308,534, this device is complex and difficult to adjust. In my earlier U.S. Pat. No. 5,669,482, an adjustable contact shoe for power rails is shown that can raise or lower itself as it travels over the power rail. However, the shoe can only move vertically, through a limited height, and cannot flip out of the way if an obstruction such as the rail covering board accidentally drops onto the power rail. Therefore, no prior art discloses a contact shoe assembly which can accommodate an upwardly-facing power rails, and flip backwards, out of the way if an obstruction, such as a rail board drops onto the power rail.